白菜叶片表皮蜡粉成分及合成相关基因表达分析

摘要

为了解白菜叶片表皮蜡粉晶体结构形态、成分及合成,以有蜡粉的R-o-18和无蜡粉的15E-545-2为试材,利用扫描电镜观察成熟期新鲜叶片表皮的晶体结构;采用气相色谱-质谱联用(GC-MS)分析二者在蜡粉成分上的差别,以峰面积为指标,定量计算蜡粉组分含量.结果表明:5000×下R-o-18上下表皮的蜡粉晶体均呈致密的面包屑状,大小约为10μm;15E-545-2则没有观察到类似结构.GC-MS分析结果表明,R-o-18成熟期叶片表皮蜡粉成分中含酮类2种,占表皮蜡粉提取物的1.02%;醇类4种,占8.33%;烷烃10种,占55.09%;酯类2种,占26.34%.15E-545-2中检测到酮类1种,占3.83%;醇类3种,占9.17%;脂肪酸4种,占23.29%;烷烃1种,占9.32%.蜡粉合成途径Bra034583、Bra018412、Bra032670、Bra027907、Bra027906、Bra027904、Bra027902基因在两个材料中都呈先升后降的表达趋势;且蜡粉性状显现期在R-o-18中的表达均高于15E-545-2,初步证明此7个基因是与白菜叶片表皮蜡粉合成相关的基因.%In order to understand the cuticular wax structure morphology,components and compound of Brassica rapa L.,this paper took'R-o-18'(in waxy)and'15E-545-2'(in glossy)as material and observed the crystal texture of fresh leaves cuticule by scanning electron microscope,analyzed the differences between these 2 wax components with GC-MS,and quantitatively calculated wax content taking peak area as target.The results showed that the waxy crystals on both side of'R-o-18'leaf surface showed a dense breadcrumbs-like structure.5000 times could clearly see the crystal showing breadcrumbs, and the size was about 10 μm. No similar structure was observed on'15E-545-2'.The results of GC-MS showed that there were 2 ketones in wax powder of'R-o-18',accounting for 1.02% of the extract of epidermal wax powder.And 10 alkanes accounted for 55.09%,4 alcohols accounted for 8.33%,2 esters accounted for 26.34%,respectively.Fatty acid was the major component of'15E-545-2',accounting for 23.29%.And ketone,alcohol,alkane accounted for 3.83%,9.17%,9.32%,respectively.Seven genes(Bra034583,Bra018412,Bra032670,Bra027907,Bra027906,Bra027904,Bra027902) mentioned above in both material showed the tendency of increasing first then declining.And in the waxy traits appearing period,the above mentioned genes expression in'R-o-18'was higher than that in'15E-545-2'. These results preliminary proved that these 7 genes did paly roles in synthesis of leaf cuticular wax.